Now it fell at that time that Sir Launcelot heard of a jousting hard by his castle, and he sent word thither that there was one knight in the Joyous Isle, by name "The knight that hath trespassed," that will joust against any knights that will come to him. When this cry was made, unto Joyous Isle drew many knights, and wit you well there was not seen at Arthur's court one knight that did so much deeds of arms as were done in that gay castle.
And in the meanwhile came also Sir Percivale nigh to Joyous Isle, and would have gone to that castle, but might not for the broad water. Then he saw on the other side a lady, and he called unto her and asked who was in that castle.
"Fair knight," she said, "here within this castle is the fairest knight and the mightiest man that is, I dare say, living, and he calleth himself 'The knight that hath trespassed.' He came into this country like a mad man, with dogs and boys chasing him, and by miracle he was brought into his wit again. If ye list to come into the castle, ye must ride unto the farther side of the isle, and there ye shall find a vessel that will bear you and your horse."
Then Sir Percivale came unto the vessel, and passed the water. When he came to the castle gate, he bade the porter, "Go thou to the good knight within the castle, and tell him here is come an errant knight to joust with him."
Sir Percivale now rode within the castle, and anon Sir Launcelot had warning, he was soon ready. And there Sir Percivale and Sir Launcelot encountered with such a might that both the horses and the knights fell to the earth. Then they left their horses, swung out noble swords, and hewed away pieces of their shields, and dashed together like two boars, and either wounded other passing sore.
At the last Sir Percivale spake, when they had fought there more than two hours: "Fair knight," saith he, "I pray thee tell me thy name, for I met never with such a knight."
"Sir," said Sir Launcelot, "my name is 'The knight that hath trespassed.' Now tell me your name, I pray you, gentle knight."
"Truly," said Sir Percivale, "my name is Sir Percivale of Galis; King Pellinore was my father and Sir Aglovale is my brother."
"Alas," said Sir Launcelot, "what have I done to fight with you that art a knight of the Table Round, that sometime was your fellow."
Therewithal Sir Launcelot kneeled down upon his knees, and threw away his shield and his sword from him. When Sir Percivale saw him do so, he marvelled what he meant. Then he begged him upon the high order of knighthood to tell his true name, and Sir Launcelot told him all.